Article
Engineering, Electrical & Electronic
Rui Xiong, Xiangchao Zhang, Xinyang Ma, Leheng Li, Lili Qi, Jian Wang, Xiangqian Jiang
Summary: The proposed method based on polarized coded aperture correlation holography enables full-dimensional measurement, allowing for the restoration of three-dimensional images as well as the calculation of Stokes parameters, surface topography, and reflectivity simultaneously.
IEEE PHOTONICS JOURNAL
(2022)
Article
Optics
Rui Yang, Shuai Wan, Yangyang Shi, Zejing Wang, Jiao Tang, Zhongyang Li
Summary: This paper discusses the potential and challenges of introducing metasurfaces onto optical waveguide integration, and proposes a series of novel on-chip metaoptics functionalities. By utilizing computer-generated holograms and water immersive tuning, dynamic tuning and switchable ability between arbitrary-encoding channels are achieved, expanding the encoding freedom.
LASER & PHOTONICS REVIEWS
(2022)
Review
Optics
Hui Gao, Xuhao Fan, Wei Xiong, Minghui Hong
Summary: Holography is an ideal approach for future deep-immersive naked-eye display, but traditional holographic devices have shortcomings. Metasurfaces, composed of subwavelength unit cells, show great potential in manipulating light fields to overcome these drawbacks. Emerging applications of dynamic meta-holography may accelerate the development of light field manipulation and micro/nanofabrication.
OPTO-ELECTRONIC ADVANCES
(2021)
Article
Astronomy & Astrophysics
Xavier Bekaert, Andrea Campoleoni, Simon Pekar
Summary: We demonstrate that the on-shell (electric) conformal Carrollian scalar in any space-time dimension can be understood as the flat-space limit of the singleton representation from the conformal algebra. Furthermore, we establish a connection between the recently proposed higher-spin algebra for Minkowski spacetime and the Poincare enveloping algebra on the corresponding module. This higher-spin algebra is a contraction of the algebra used in Vasiliev's equations and can be constructed similarly from the singleton representation of the conformal algebra. Additionally, we show that the higher-spin extension of the Poincare algebra considered by us is a subalgebra of the symmetries of the conformal Carrollian scalar, represented by a higher-spin version of the (extended) BMS algebra.
Article
Astronomy & Astrophysics
Naoki Ogawa, Tadashi Takayanagi, Takashi Tsuda, Takahiro Waki
Summary: In this paper, we investigate the holography of codimension two in flat spacetimes, utilizing the concept of wedge holography. We propose that a region in d + 1 dimensional flat spacetime enclosed by two d dimensional hyperbolic spaces corresponds to a conformal field theory (CFT) on a d - 1 dimensional sphere. Additionally, we suggest that a d + 1 dimensional region in the flat spacetime bounded by two d dimensional de Sitter spaces is holographically dual to a CFT on a d - 1 dimensional sphere. Through calculations of the partition function, holographic entanglement entropy, and two-point functions, we provide support for these duality relations and indicate that these CFTs are nonunitary. Finally, we merge these two dualities along null surfaces to achieve a codimension two holography for a complete Minkowski spacetime, and discuss a potential connection to celestial holography.
Article
Optics
Tomoyoshi Inoue, Koki Nagao, Kenzo Nishio, Toshihiro Kubota, Yasuhiro Awatsuji
Summary: This study proposes an imaging technique to obtain double motion-pictures of propagating light pulses with an ultrashort time difference. By employing a space-division multiplexing technique for recording holograms and introducing an optical delay setup, the technique achieves non-superposition recording of double motion-pictures.
Article
Optics
Masatoshi Imbe
Summary: This study proposes an interferometric method using conventional optical components for single-pixel imaging of a spatially incoherent light source. Experimental results confirm that this method enables reconstruction of images with specific spatial resolution.
Article
Optics
Zhenning Guo, Peipei Ge, Yankun Dou, Mingming Liu, Xiaoxiao Long, Jiguo Wang, Qihuang Gong, Yunquan Liu
Summary: In this study, we experimentally demonstrate the correlation between the photoelectron momentum distributions and the phase structure of the electron wave packet at the ionization exit for multiphoton ionization of aligned N-2 molecules. By examining the two-color phase-resolved photoelectron interference fringes, we observe a relative phase shift between above-threshold ionization and sideband peaks, which depends on the molecular alignment angle. Furthermore, we show that the initial phase, which is determined by the molecular orbital at the ionization exit, can be modulated by the two-color synthesized fields and decreases with increasing photoelectron energy. The alignment-dependent phase shift in momentum space enables the retrieval of the relative spatial displacement for electrons at the ionization exit in position space between different alignments.
Article
Multidisciplinary Sciences
Ravi Kumar, Vijayakumar Anand, Joseph Rosen
Summary: Interferenceless coded aperture correlation holography (I-COACH) techniques have revolutionized incoherent imaging by offering high-resolution multidimensional imaging capabilities with a simple optical configuration and low cost. The I-COACH method uses phase modulators to encode 3D location information into unique spatial intensity distributions, allowing for object reconstruction using recorded point spread functions (PSFs). Previous versions of I-COACH suffered from low signal-to-noise ratios and reduced imaging resolution due to the use of scattered intensity distributions or random dot array patterns. This study introduces I-COACH using a phase modulator that maps each object point into a sparse random array of Airy beams, resulting in improved SNR and sharper intensity distributions.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Simcha K. Mirsky, Natan T. Shaked
Summary: Six-pack holography is used to reject out-of-focus objects in dynamic samples by illuminating the sample from six different angles and pixel-wise averaging the reconstructed images. This significantly reduces the contribution of out-of-focus objects by up to 83%, improving system sectioning capabilities.
Article
Optics
Jung-Ping Liu, Chieh-Cheng Lee, Yaping Zhang, Yongwei Yao, Ting-Chung Poon
Summary: We have developed a system for off-axis optical scanning holography (OSH) and successfully recorded holograms without using heterodyning or a spatial light modulator for temporal frequency shifting. A phase monitoring module is included to mitigate phase fluctuation. Reconstruction without the zeroth-order light and the twin image is achieved through single sideband filtering and phase compensation. The coherent-mode and incoherent-mode properties and practical issues of off-axis OSH are also discussed.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Kexuan Liu, Zehao He, Liangcai Cao
Summary: The study reveals that the reconstruction quality depends on the uniform amplitude value for different object patterns and proposes a pattern-adaptive BERD algorithm for high-quality holographic reconstruction. The optimized amplitude value can be acquired for each object pattern and propagation distance, resulting in higher reconstruction quality compared to traditional BERD-based approaches.
CHINESE OPTICS LETTERS
(2021)
Article
Astronomy & Astrophysics
D. Giataganas, N. Tetradis
Summary: In this study, holography was used to investigate the entanglement entropy for a spherical entangling surface in a FRW background with an arbitrary time dependence of the scale factor. The calculations were performed in various dimensions, including nonzero spatial curvature, and also considered the entanglement entropy of a CFT at nonzero temperature in this background. The approach is based on coordinate transformations that relate the extremization problem to the one for a static background, with careful determination of the UV cutoff, and demonstrated agreement with expected forms and known results in specific cases, including computation of the finite term related to the expansion rate in four dimensions.
Article
Physics, Multidisciplinary
Sergio Hernandez-Cuenca, Gary T. Horowitz, Gabriel Trevino, Diandian Wang
Summary: Even for holographic theories that abide by boundary causality, there are metrics in the full bulk Lorentzian path integral that violate this condition, leading to a puzzle regarding the commutator of field theory operators. However, a careful treatment of boundary conditions in holography reveals a natural resolution to this puzzle through the bulk path integral.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Applied
Ya-Nan Zhao, Li Wang, Shuang-Long Bian, Sheng-Wei Cui, De-Zhong Cao, Bao-Lai Liang, Hong-Chao Liu, Su-Heng Zhang
Summary: Researchers propose a dual-modal SPI system that can simultaneously capture the real-part and magnitude images of objects. The system has strong information acquisition capability and is simple, efficient, and fast.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Surya Kumar Gautam, Rakesh Kumar Singh, C. S. Narayanamurthy, Dinesh N. Naik
Article
Optics
Surya Kumar Gautam, Rakesh Kumar Singh, C. S. Narayanamurthy, Dinesh N. Naik
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2020)
Article
Optics
Abhijit Roy, Rakesh Kumar Singh, Maruthi M. Brundavanam
Article
Optics
R. V. Vinu, Ziyang Chen, Rakesh Kumar Singh, Jixiong Pu
Article
Optics
Joseph Rosen, Hilton B. de Aguiar, Vijayakumar Anand, YoonSeok Baek, Sylvain Gigan, Ryoichi Horisaki, Herve Hugonnet, Saulius Juodkazis, KyeoReh Lee, Haowen Liang, Yikun Liu, Stephan Ludwig, Wolfgang Osten, YongKeun Park, Giancarlo Pedrini, Tushar Sarkar, Johannes Schindler, Alok Kumar Singh, Rakesh Kumar Singh, Guohai Situ, Mitsuo Takeda, Xiangsheng Xie, Wanqin Yang, Jianying Zhou
Summary: In recent years, the rapid development of chaos-inspired imaging technologies, consisting of non-invasive and invasive directions, has led to faster and smarter imaging capabilities. Non-invasive imaging through scattering layers has achieved significant progress, while invasive imaging exploits chaos to achieve special imaging characteristics and increase dimensionalities beyond the limits of conventional imagers. This roadmap presents the current and future challenges in both invasive and non-invasive imaging technologies.
APPLIED PHYSICS B-LASERS AND OPTICS
(2022)
Article
Physics, Multidisciplinary
Li Chen, Rakesh Kumar Singh, R. V. Vinu, Ziyang Chen, Jixiong Pu
Summary: The proposed method utilizes wavefront division multiplexing to achieve dual wavefront modulations on a single SLM, allowing flexible modulation of reference light. This simplifies experimental configuration and improves stability, opening new possibilities for holography-based scattering imaging applications.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Li Chen, Ziyang Chen, Rakesh Kumar Singh, R. V. Vinu, Jixiong Pu
Summary: Quantitative phase imaging (QPI) is essential for exploring properties of transparent and absorption-free samples, with holography widely used to record both amplitude and phase of optical fields. However, conventional holographic methods face challenges when objects are obscured by scattering media. Advanced holographic methods based on Hanbury Brown-Twiss (HBT) approach, such as off-axis holography, phase-shifting holography, and polarization-based phase-shifting holography, show enhanced imaging capabilities and wider field of view in comparison. The use of orthogonally-polarized light as reference light in the third method demonstrates superior performance in imaging complex phase samples.
OPTICS AND LASERS IN ENGINEERING
(2022)
Article
Optics
Tushar Sarkar, Reajmina Parvin, Maruthi M. Brundavanam, Rakesh Kumar Singh
Summary: In this Letter, a new, non-interferometric and highly stable technique is proposed and experimentally demonstrated to unscramble the incident orbital angular momentum (OAM) state and quantitatively measure the phase structure from non-imaged random light. A new theoretical basis is developed, validated by numerical simulation and experimental demonstration, to quantitatively investigate the OAM modes of the incident light.
Article
Optics
Sushanta Kumar Pal, Rakesh Kumar Singh, P. Senthilkumaran
Summary: This paper analyzes the focusing behavior of ellipse fields with C-point singularities, and finds that the sign and absolute value of the C-point index play an important role in tailoring the focal intensity distribution. The intensity distribution of the longitudinal component shows symmetries corresponding to the number of separatrices in the polarization distribution.
Article
Chemistry, Multidisciplinary
Yanyan Huang, R. V. Vinu, Ziyang Chen, Tushar Sarkar, Rakesh Kumar Singh, Jixiong Pu
Summary: A new holographic ghost diffraction scheme is proposed and experimentally demonstrated for the recovery of OAM modes, utilizing speckle fields and fourth-order correlation. The efficacy of the recovered modes is quantitatively analyzed with an OAM mode analysis utilizing orthogonal projection scheme.
APPLIED SCIENCES-BASEL
(2021)
Article
Multidisciplinary Sciences
Aditya Chandra Mandal, Tushar Sarkar, Zeev Zalevsky, Rakesh Kumar Singh
Summary: This paper presents a new method for reconstructing the complex coherence function in coherence holography without an interferometric setup. The technique, named structured transmittance illumination coherence holography (STICH), uses structured pattern projections and single-pixel detectors to measure the intensity cross-covariance and reconstruct the complex coherence. A simple experimental setup and computer modeling results are presented to validate the idea.
SCIENTIFIC REPORTS
(2022)
Letter
Optics
Tushar Sarkar, Sourav Chandra, Vipin Tiwari, Nandan S. Bisht, Bhargab Das, Rakesh Kumar Singh
Summary: In this paper, we propose and experimentally demonstrate an on-axis phase-shifting correlation holography technique with un-polarized light. The randomness of the un-polarized light is utilized to evaluate higher-order polarization correlation and reconstruct holograms. The technique is verified through theoretical analysis, numerical simulations, and experimental demonstrations. The imaging results of different helical phase objects with randomness show good agreement between simulations and experiments, confirming the accuracy of the proposed technique.
Article
Optics
Manish, Vipin Tiwari, Nandan S. Bisht, Bhargab Das, Rakesh Kumar Singh
Summary: We present a new method for reconstructing a two-dimensional object in the Ghost diffraction scheme using a spatial statistical optics approach. Instead of a rotating diffuser, a static diffuser is used to generate a pseudo thermal light source, improving the conventional ghost imaging systems. By exploiting spatial ergodicity and spatial stationarity of spatially distributed random fields, we establish an analogy between time average and space average. The ensemble average is replaced by space average under the condition of spatial stationarity and ergodicity. This allows us to reconstruct the transparency of the object by implementing the Ghost diffraction scheme through spatial intensity correlation with a phase retrieval algorithm.
OPTICS COMMUNICATIONS
(2023)
Article
Optics
Tushar Sarkar, Vipin Tiwari, Sourav Chandra, Nandan S. Bisht, Rakesh Kumar Singh
Summary: This paper presents a holography technique based on higher-order Stokes correlation and demonstrates its application through experiments. The proposed technique is capable of reconstructing complex-valued objects from random light fields and overcomes twin image issues in higher-order correlation holography.
Article
Optics
Tushar Sarkar, Reajmina Parvin, Maruthi M. Brundavanam, Rakesh Kumar Singh
Summary: A non-interferometric method was proposed and experimentally demonstrated to quantitatively determine the topological charge and complete phase structure of a vortex beam scattered by random media. The theoretical basis developed was supported by numerical simulations and experimental results, with good agreement between them. The technique involves coupling spatial and polarization modes of coherent light before entering the scattering medium and retrieving complex polarization correlation functions to reconstruct twisted wavefronts.
